feat: add SQLite support, setup wizard enhancements, and live dashboard

Add zero-dependency SQLite mode so users can run Erupe without
PostgreSQL. A transparent db.DB wrapper auto-translates PostgreSQL
SQL ($N placeholders, now(), ::casts, ILIKE, public. prefix,
TRUNCATE) for SQLite at runtime — all 28 repo files use the wrapper
with no per-query changes needed.

Setup wizard gains two new steps: quest file detection with download
link, and gameplay presets (solo/small/community/rebalanced). The API
server gets a /dashboard endpoint with auto-refreshing stats.

CI release workflow now builds and pushes Docker images to GHCR
alongside binary artifacts on tag push.

Key changes:
- common/db: DB/Tx wrapper with 6 SQL translation rules
- server/migrations/sqlite: full SQLite schema (0001-0005)
- config: Database.Driver field ("postgres" or "sqlite")
- main.go: SQLite connection with WAL mode, single writer
- server/setup: quest check + preset selection steps
- server/api: /dashboard with live stats
- .github/workflows: Docker in release, deduplicate docker.yml

.github/workflows/release.yml

@@ -7,6 +7,13 @@ on:
 
 permissions:
   contents: write
+  packages: write
+  attestations: write
+  id-token: write
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
 
 jobs:
   build:
@@ -56,9 +63,49 @@ jobs:
         path: erupe-${{ matrix.os_name }}.zip
         retention-days: 1
 
+  docker:
+    name: Build and Push Docker Image
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v4
+
+    - name: Log in to the Container registry
+      uses: docker/login-action@v3
+      with:
+        registry: ${{ env.REGISTRY }}
+        username: ${{ github.actor }}
+        password: ${{ secrets.GITHUB_TOKEN }}
+
+    - name: Extract metadata (tags, labels) for Docker
+      id: meta
+      uses: docker/metadata-action@v5
+      with:
+        images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+        tags: |
+          type=semver,pattern={{version}}
+          type=semver,pattern={{major}}.{{minor}}
+
+    - name: Build and push Docker image
+      id: push
+      uses: docker/build-push-action@v6
+      with:
+        context: .
+        push: true
+        tags: ${{ steps.meta.outputs.tags }}
+        labels: ${{ steps.meta.outputs.labels }}
+
+    - name: Generate artifact attestation
+      uses: actions/attest-build-provenance@v2
+      with:
+        subject-name: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+        subject-digest: ${{ steps.push.outputs.digest }}
+        push-to-registry: true
+
   release:
     name: Create Release
-    needs: build
+    needs: [build, docker]
     runs-on: ubuntu-latest
 
     steps:
@@ -76,6 +123,15 @@ jobs:
       uses: softprops/action-gh-release@v2
       with:
         generate_release_notes: true
+        body: |
+          ## Docker Image
+
+          This release is also available as a Docker image:
+
+          ```bash
+          docker pull ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ github.ref_name }}
+          ```
+        append_body: true
         files: |
           artifacts/Linux-amd64/erupe-Linux-amd64.zip
           artifacts/Windows-amd64/erupe-Windows-amd64.zip